oracle數據庫sql語句實現重複記錄刪除

-- 查詢及刪除重複記錄的SQL語句
-- 1、查找表中多餘的重複記錄，重複記錄是根據單個字段（Id）來判斷
select * from 表 where  Id in (select Id from 表 group by Id having count(Id) > 1)
 
-- 2、刪除表中多餘的重複記錄，重複記錄是根據單個字段（Id）來判斷，只留有rowid最小的記錄
DELETE from 表 WHERE (id) IN ( SELECT id FROM 表 GROUP BY id HAVING COUNT(id) > 1) AND ROWID NOT IN (SELECT MIN(ROWID) FROM 表 GROUP BY id HAVING COUNT(*) > 1);
 
-- 3、查找表中多餘的重複記錄（多個字段）
select * from 表 a
where (a.Id,a.seq) in (select Id,seq from 表 group by Id,seq having count(*) > 1)
-- 4、刪除表中多餘的重複記錄（多個字段），只留有rowid最小的記錄
delete from 表 a
where (a.Id,a.seq) in   (select Id,seq from 表 group by Id,seq having count(*) > 1)
and rowid not in (select min(rowid) from 表 group by Id,seq having count(*)>1)
-- 5、查找表中多餘的重複記錄（多個字段），不包含rowid最小的記錄
select * from 表 a
where (a.Id,a.seq) in   (select Id,seq from 表 group by Id,seq having count(*) > 1)
and rowid not in (select min(rowid) from 表 group by Id,seq having count(*)>1)